The ceramic membrane with 5 nm pore size was applied to the treatment of wastewater containing La3+ produced from metallurgical,electronics and chemical industries.Effects of ion concentration,electrolyte and solution pH on the separation performance of membrane were investigated.Results showed that with the increase of La3+ concentration,permeate increased and permeate flux decreased.When the La3+ mass concentration increased from 9.1 mg/L to 245.0 mg/L,the rejection rate of La3+ was decreased 82.4% to 66.2%,the flux decreased about 5%.The addition of electrolyte had a drastic adverse effect on the rejection performance of ceramic membrane.With the increase of NaCl concentration,the rejection rate of La3+ decreased and the permeate flux increased.When the NaCl mass concentration was up to 100 mg/L,the rejection rate of La3+ decreased from 69.3% to 26.0%,while the permeate flux increased more than 30%.The pH of the solution influenced the property of the membrane surface charge and changed forms of the lanthanum existence in solution. When pH<6, lanthanum was mostly existed in the form of La3+.It was mostly La(OH)3 precipitates in solution and correspondingly the rejection rate of La3+ was above 99% at pH 10. There was a fraction of La(OH)2+ generated on pH values in the range of 6 to 8,thus increasing the pore blocking resistance and reducing the permeate flux.Adjusting solution pH value could contribute to recovering lanthanum ions in wastewater by ceramic ultrafiltration membrane and realized resourceful utilization.